Methodology to Develop Median Barrier Warrant Criteria

Abstract

Median design policies for high-speed, divided highways are investigated to assess existing median barrier warrant criteria. Safety and cost-effectiveness analyses were conducted to determine relationships between median-related crashes and geometric and traffic operational variables. Count regression models were used to estimate the safety performance of divided highway sections with and without longitudinal median barrier. Crash severity models of cross-median and median barrier crashes were estimated using logistic regression. Modeling results were incorporated into a benefit-cost model to assess median design practices using Pennsylvania Interstate highway data. Although varying with traffic volumes, the installation of median barrier along roadway sections with median widths up to 21.3 m (70 ft) wide can produce safety and economic benefits.